Lamp shade seam sealing machine



p 1953 J. J. CAHILL 2,65

LAMP SHADE SEAM SEALING MACHINE I Filed March 6, 1950 2 Sheets-Sheet 1 A NIHH HIHIHI H HH INVENTOR.

Ja/m I ('a'iu'll Se t. 15, 1953- J- J. CAHILL LAMP sum: SEAM SEALING MACHINE Filed March 6, 1950 2 Sheets-Sheet 2 Patented Sept. 15, 1953 LAMP SHADE SEAM SEALING MACHINE John J. Cahill, New York, N. Y., assignor to Mutual Machine Company, New York, N. Y., a

copartnership Application March 6, 1950, Serial No. 147,958

4 Claims.

IMy present invention relates to seam-sealing machines and more particularl to lampshade seam-sealing machines, and aims to provide certain improvements therein.

In the manufacture of lamp shades from paper, parchmentized paper, synthetic plastic and the like, it is customary to assemble the component elements of a shade, usually two wire rings and a sheet or lamp shade material cut to desired size, the top of one of said rings frequently being formed with a diametrical crossbar and a pair of depending wire loops adapted to snap over an electric light bulb, which serves to retain the shade on the lamp stand. The assembling of the rings withthe shade material may be performed either by hand or by machine. The lamp shade material is usually cut slightly larger than the circumferences of the wire rings to provide overlapping ends which must be seamed or sealed to present a smooth,

outer contour and pleasing finished appearance to the shade. Accordingly, at least one of the ends which are to be lapped is first coated with adhesive, where the material used is not capable of self-sealing under heat, the top and bottom of the material are affixed to the wire rings, in the course of which the ends are brought into overlapping relation and said overlapping ends are subsequently subjected to heat and pressure to effect the sealing.

In all prior machines with which I am familiar, wherein the means for efiecting the-seamsealing of the lamp shade, comprisepressure elements, said pressure elements must avoid contact with the wire rings which normally interfere with the pressure elements making effective contact with the overlapping ends ofthe sheet material. Hence different lengths of pressure sealing units had to be employed, depending on the length of the seam between the wire rings. Be-

cause of the types of machines heretofore employed and the procedure which had to be followed, the seaming operation required a multiplicity of pressure units, extreme care in posi- .tioning the seam u n the pressure unit and hence were time-consuming and costly.

The primar object of the present invention is to provide a machine wherein the above noted deficiencies in lamp shade seam-sealing machines are overcome. A further object is to provide a machine of the character set forth having a universal pressure unit wherewith lamp shade seams of any length within .the limitations of the machine can be expeditiously and neatly sealed.

The foregoing and other objects of myinvention not specifically enumerated I accomplish by providing a machine of the character specifled having a pressure unit formed with compensating means which, upon engagement with the wire rings of a lamp shade or the like, yield to permit the remainder of the lamp shade engaging portions of the pressure unit to smoothly seal the entire seam between the wire rings. The invention will be better understood from the detailed description which follows, when considered in connection with the accompanying drawings wherein:

Figure 1 is the side elevation of a lamp shade seam-sealing machine embodying my invention.

Fig; 2 is a fractional topple-n of the machine shown in Fig. 1. i

Fig. 3 is a perspective view of a lamp shade of a' type adapted for seam-sealing on the machine of the present invention. 1 Fig. 4 is a sectional elevation of an'enlarged scale of the operating mechanism of the machine shown in Figs. 1 and 2, the supporting table being omitted. I

Fig. 5 is a transverse section taken substantially along'the plane of the line -5-5 of Fig. 4,

the protective sheathing of the upper pressure element being omitted.

Referring to the drawings, a lamp shade seamsealing unit Ill issupported upon abase I adapted wee securely "mounted on a work bench or table 12 having supporting legs l3 and reinforcingcross-arrns H and H. Secured upon the base I I "is a" supplementary'base plate [5 formed with a pairof spaced, "upstanding earsjlfi integrally connected at their bases by a reinforcing cross-piece [1 having a cylindrical opening ,or bore l8 therethrough. In alignmentwith the bore lathe, base plate 45 is formed with a socket [9 for supporting one-end of 'a compression'coilspring 20. Also in alignment withthe bore la the base H is formed with an opening 21 in which is fixedly mounted "a cylindrical sleeve '22 which serves as a guide for a plunger 23,.which,

at its upper end, carries a ring 24 having a projecting nose 2-5, the said ring being held on a reduced portion ofthe'plunger bya nut 26. The lower end of the plunger 23 bifurcated and has pivotally mounted insaid bifurcation through a pin 27, a lever 28, one end 29 of which is pivotallyccnnected to a fined arm 36 dependfingly mounted on the under face of the base II. The other end 3| of the lever 28 is pivotallyconnected to one endof 'a'pull rod 32, the opposite end-of whichi's pivotally connected 3 to a foot treadle 33, the end 34 of which is pivotally connected to a bracket 35 mounted on a reinforcing arm l4. It will thus be seen that, upon pressing downwardly on the treadle 33, the plunger 23 is moved downwardly. To accommodate the downwardly projecting end of the sleeve 22 and the downwardly extending fixed arm 30, the table I2 is suitably recessed, as shown respectively at 35 and 35.

Mounted over the top of the spring 25 is a cap 31 and surrounding said cap so as to move relatively thereto is a casting 38 having a substantially elliptical opening 39 encompassing said cap, said casting having a sleeve 40 projecting from one side thereof, within which is secured by set screws 4| a tubular rod 42, the sleeve and rod being pivotally supported between the ears l by a pin 43. Extending through the casting diametrically opposite the sleeve 40 and at a right angle to the axis of said sleeve, is an adjustable screw 44 which supports a ball 45 against the under side of the nose '25. The casting 38 is pivotally secured to the cap 31 through a pair of diametrically disposed set screws 46, the inner ends of which are tapered and engage in a pair of diametrically disposed tapered openings 41 in the cap 31. The set screws 45 are held in fixed relation to the cap 31 by lock nuts 48 to permit relative pivotal movement oetween the casting 38 and the cap.

The pressure applying unit of the machine consists of an upper element or platen 45 and a lower element or platen 50, the said elements being of generally longitudinal form and having complementary surfaces 5| and 52 which, in transverse section, are of flattened, arcuate form, as best shown in Fig. 5. The upper element 45 is of channel or U-shape form in transverse section and is reinforced and supported by a bar 53, which, in turn, is supported by a U-shaped bracket 54 by bolts 55, the ears of the bracket 54 straddling and being pivotally connected to a rectangular block 55 through a pivot pin 51, the block having an axial bore therethrough within which one end of the rod 42 extends and is held by the pin 51. Preferably the bearing or pressure surface 5| of the upper element 45 of the clamping unit is covered with a protective fibrous covering 58 so as to prevent marking or scoring of the outer surface of the lamp shade along the line of seal. The fibrous covering may be held onto the upper element 49 in any preferred manner, and is herein shown as being laced thereto, the upper element being suitably formed with pins 53 around which the laces may be tensioned. The lower element 50 of the clamping unit consists of a strong, rigid supporting bar 55 of general rectangular section, the right hand end thereof 65 being of cylindrical form and snugly fitting within the bore l5 of the reinforcing member l1 and suitably secured therein.

The complementary surface 52 of the lower element of the clamping unit is preferably formed of a plurality of independent depressible members 5| arranged in an unbroken sequence, each of said members being biased by a coil-spring 52 mounted in a socket 5| in a supporting bar 53, the said springs acting to normally press the engaging surfaces of the constituent members 5| outwardly, and means being provided for limiting said outward movement so that the composite engaging surfaces of the individual members 5| will normally lie fiush with one another to provide the surface 52. To accomplish this, the movable members are mounted on the supporting bar 53 having overhanging flanges 54, the movable members being of generally inverted U-shaped form in cross-section and having in turned flanges 55 engaging under the flanges 54. The supporting bar 53 extends the full length of the plurality of adjacently abutting independently depressible members 5| and is suitably secured to the rigid bar 55 by cleats 55 or equivalent means. To effectively seal the overlapping ends of a lamp shade or other member whether said ends have adhesive applied thereto or are of the thermoplastic type, it is desirable to heat the lower element of the pressure applying unit, and to accomplish this the bottom of the supporting bar 53 is formed with a channel 53' within which is positioned an electric heating unit 51. To insulate the heated supporting bar 53 from the rigid bar 59, a strip of asbestos board 55 or the like may be interposed between the bars 59 and 53. The parts 50, and 59 to 55, inclusive, constitute what may be termed a fixed horn projecting from the support and over which horn the lamp shade to be seam-sealed is positionable in performing the seam-sealing operation. A suitable connecting plug 59 having lead-in wires 10 are connected to the heating element and adapted for insertion in a suitable outlet to supply electrical energy to the heating element.

In the use of the machine the movable upper element 45 of the clamping unit is held with its pressure surface 5| in complementary engagement with the surface 52 of the fixedly held lower element of the clamping unit by the force of the spring 20 acting upon the rod 42 which is pivotally connected to the upper element of the clamping unit and which rod 42 is fulcrumed on the pivot pin 43. The lower element of the clamping unit is heated by the heating unit 51 by the plug 59 being inserted in a suitable elec-- tric current supply outlet (not shown). When it is desired to seal the seam at the overlapping ends of a lamp shade or the like, an operator depresses the treadle 33, which, in turn, acting through the rod 32 and lever 25, draws the plunger 23 downwardly, whereupon the nose 25 presses downwardly upon the ball 45 to pivot the casting 35 about the pivot pin 43, to overcome the tension of spring 20 and raise the upper clamping element 49 away from the lower clamping element 50. The operator then inserts between the spaced apart clamping elements over the left hand end of the fixed element or form as shown in Fig. 1, the assembled elements of the lamp shade, as shown in Fig. 3, with the overlapping ends 14 and 15 disposed over the surface 5| of the fixed heated clamping element. Upon releasing pressure upon the treadle the spring 20 presses the upper clamping element into engagement with the outer surface of the lamp shade, which pressure, together with the heat, is sufficient to seal the seam. In this operation the wire rings 1| and 12, which are of greater thickness than the overlapped ends of the lamp shade material, do not interfere with the sealing operation since the downward pressure of the upper clamping element upon said rings will cause them to depress the independently movable members of the lower clamping element which they contact and thereby cause uniform pressure to be applied throughout the entire length of the seam. After the clamping elements have remained in clamping position upon the lamp shade seam for a predetermined interval of time, usually a few seconds, the operator again depresses the treadle and removes the lamp shade from the machine.

By virtue of the fact that extreme care need not be exercised in positioning the preassembled lamp shade unit between the clamping elements of the machine so as to avoid contact with the wire rings, it will be appreciated that the lamp shades may be quickly and eificiently seamsealed. The protective covering 58 on the upper clamping element serves to prevent marring of the outer surface of the lamp shade and the resulting sealed seam therefore presents a neat and finished appearance.

While I have shown and described a preferred embodiment of my invention it is to be understood that I do not wish to be limited to the details of construction herein disclosed since the same may be varied within the range of mechanical skill without departing from the spirit of the invention as claimed.

What I claim is:

1. A lamp shade seam-sealing machine having a stationary support, a pressure applying unit mounted on said support, said pressure applying unit having a pair of platens with complementary surfaces between which overlapped ends of the members to be sealed are positionable, and means for applying sealing pressure to the complementary surfaces of said platens, characterized in that one of the platens comprises a fixed horn having a free end projecting laterally from the support and over said free end a tubular lamp shade to be seam-sealed is positionable, said horn comprising a rigid bar, an unbroken sequence of laterally abutting, independently depressible members mounted on said rigid bar and adapted for limited transverse movement relatively thereto, said rigid bar having a row of sockets therein, one such socket for each depressible member, a spring in each socket biasing a depressible member outwardly, and cooperating means on the rigid bar and on the depressible members for limiting the out- Ward movement of the depressible members so that the work engagement surfaces thereof will normally lie flush with one another to provide the work engagement surface of said horn.

2. A lamp shade seam-sealing machine according to claim 1 wherein the horn has heating means therein for heating the work engagement surface of the horn.

3. A machine particularly adapted for seamsealing the overlapped ends of a tubular lamp shape having a peripheral wire reinforcing ring, said machine comprising a stationary support, a pressure-applying unit mounted on and laterally projecting from said support, said pressure-applying unit having a pair of platens with complementary surfaces between which the overlapped ends of a lamp shade to be sealed are positionable, means for applying and distributing sealing pressure to the complementary surfaces of said platens across the entire areas thereof, one of said platens having a nondeformable pressure-applying face and the other of said platens comprising an unbroken sequence of abutting, independently depressible members providing a normally unbroken smooth engagement surface of said platen, a separate spring means biasing each of said depressible members to normally move it outwardly and means for limiting said outward movement of the depressible members so that the engagement surfaces thereof will normally lie flush with one another and be complemental to the surface of said first platen, whereby, in the use of the machine, a depressible member of said other platen, upon encountering a wire ring of the lamp shade, will be moved out of its flush relationship to the other depressible members without affecting the sealing pressure of the platens along the remainder of the seam.

4. A machine according to claim 3 wherein one of the pair of platens is fixed and the other is movable toward and away from the fixed platen and wherein the fixed platen is the one provided with the independently depressible members, and a heating means within one of said platens for heating the surface thereof that is complementary to the surface of the other platen.

JOHN J. CAHJ'LL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 916,140 Fulton Mar. 23, 1909 1,932,083 Nichols Oct. 24, 1933 2,175,031 Salfisberg Oct. 3, 1939 2,371,847 Saunders Mar. 20, 1945 2,541,696 George Feb. 13, 1951 2,556,709 Schultz June 12, 1951 

